In offshore technologies, use is made of floating vessels for storage and/or production of hydro-carbon fluids, from undersea gas or oil fields. Such floating vessels comprise floating storage and offloading (FSO) and floating production, storage and offloading (FPSO) vessels.
Such a floating vessel may be secured at its operational position, by a structure of a number of mooring lines (or mooring legs), which connect to anchoring facilities at or in the seabed, geographically distributed i.e., spread around the position.
Alternatively, the floating vessel can be secured at its operational position by a disconnectable turret mooring system comprising a mooring buoy and a turret mooring structure. The mooring buoy is anchored to the seabed with anchoring legs. The turret mooring structure, provided on the floating vessel, has a receptacle for receiving the buoy member and one or more buoy locking devices for locking the buoy member in the receptacle.
The turret mooring structure may be an internal turret mooring structure or an external turret mooring structure. An internal turret mooring structure is provided inside the hull of the vessel, in a so-called moonpool of the vessel. The receptacle is formed as an opening at or near the bottom of the vessel, facing downwards. An external turret mooring structure is provided outside the hull of the vessel. The external turret is fixed with suitable connection members to the bow or stern of the vessel.
When the floating vessel is in operation, processing equipment on the floating vessel produces hydro-carbon fluids from sources as undersea gas or oil fields. During this operation the processing equipment uses seawater for auxiliary purposes such as cooling.
From the prior art seawater intake systems are known. For example WO2010010500 discloses a seawater suction system that comprises first and second conduits that can be linked together to form a hose. The first and second conduits are each formed from different materials.
WO2002102653 discloses a vessel riser system assembly. The assembly is made up generally of a sea chest component, a track in communication with the sea chest and the riser attachable to the sea chest. The sea chest is typically pre-fabricated and attached to the FPSO in dry dock prior to offshore operations. In particular, the sea chest is attached to the hull of the FPSO at a seawater intake grid. The track is made up of parallel first and second rails respectively which extend upwards from the sea chest, either side of the sea chest, at the sea water intake grid. The track is attached to the side of the FPSO between the FPSO deck top side and the seawater intake grid.
Both disclosures relate to water intake systems that are operational during the time that the FPSO or FLNG vessel is at fixed position in production mode.
It is an object of the present invention to overcome or mitigate the disadvantages from the prior art.